Analysis of the Crystal Gems' motives, as stated in this short:
There are all sorts of reasons men fight. Sometimes it's due to less than glorious circumstances, like a draftee who just wants to keep his head low and his mouth shut. A propaganda machine will come up with reasons that sound cooler and more noble, because no young man wants to risk his life for a lame cause. To be sure, those who fight really do believe in these causes more often than not, and they follow accordingly:
Freedom, Ideology, Homeland, Family
The Crystal Gems state explicitly in this short that for which they believe they are fighting. Each Gem cites a different cause, each representing one of the four causes listed above. They say:
Garnet: "...for the place where I'm free..."
Pearl: "...in the name of Rose Quartz..."
Amethyst: "...for the world I was made in..."
Steven: "...to be everything, that everybody wants me to be..."
Garnet: Freedom
This is perhaps one of the most common reasons a war is claimed to be fought. It is important to note, however, that "freedom" here is not being used synonymously with "Liberty". Americans, for example, tend to be very loud about how their fighting men fight for freedom, which is not necessarily untrue, but the way they use the term is typically more in line with the ideology of liberty (see below: "Pearl: Ideology"). Freedom here shall be more in line with sovereignty, the idea that one nation, people, etc. is allowed to follow its own will.
In this sense, the Nazis were fighting for freedom in the face of western domination; the Red Army fought against the Nazis in the name of Russian freedom from German domination; the Japanese were fighting for there freedom from white domination; and even the Confederate States of America were fighting for their freedom from the federal government of the United States in Washington.
In the four examples listed above was absolutely NO ONE fighting for liberty. All the causes above were either repressive, autocratic governments or otherwise went about subjugating and oppressing other peoples.
This is why Garnet fights. What she wants most in life is to be herself (as in, literally exist as Garnet, as opposed to Ruby and Sapphire). The earth is where she can do this. Whatever other values she espouses, it is of the utmost importance to her that she have her sovereignty.
Pearl: Ideology
Practically all people in the modern age fight for an ideology in one way or another, but here the term is being used to apply specifically to politically conscious soldiers who believe in very directly in the ideology itself: that is to say, fighting for freedom, country and family could all be considered their own ideologies, or tenets thereof, but that is different from a loyal Nazi who deliberately fights for National Socialism ITSELF or a North Vietnamese who deliberately fights for communism ITSELF.
It is argued that nearly every ideology can be reduced to one of three:
Liberty (high value placed on representative government and individual freedoms, e.g. democracies and republics of North America and Western Europe)
Communism (emphasis on the fact that the needs of the many outweigh those of the few, e.g. Soviet Russia, Red China)
Authoritarianism (marked by emphasis on law and order and loyalty to/respect for authority, e.g. fascist states such as Hitler's Germany or Mussolini's Italy)
Pearl is fighting first and foremost in the name of her ideology; her ideology is authoritarianism. Of all the Crystal Gems, she is perhaps the least fond of humans and the Earth, caring for them only as far as they were an interest of the mistress whom Pearl loyally served. It is as if humans and the Earth are a sort of butterfly collection of Rose's; Pearl was never much interested in butterflies or butterfly hunting, but learned to appreciate it simply because she loves all which her mistress loves. Now that Rose is gone, Pearl has inherited that butterfly collection and really does not know what to do with it. It does not really matter WHAT she thinks she is protecting; what matters most is that she is doing so in the name of Rose Quartz/Pink Diamond.
At heart, Pearl is a Homeworld Gem who loves to teach Steven about Gem history and culture and, now in the absence of Rose, longs to return to Homeworld. In the episode "Now We're Only Falling Apart", she confesses that she realized that Pink Diamond was sometimes "foolish" and "selfish"; although Pink seems to have a had a heart of gold, that does not change the fact that she was a naive princess, jealous of her older sisters and not accustomed to considering the needs of others. The episode “We Need to Talk” shows that, even after 5,000 or more years of living on earth and, according to Pearl in “Mr. Greg”, having had several romantic relationships with various men through the ages, Rose still saw humans as a quaint, charming novelty, yet she was willing to wage war on her own kind on their behalf. She is perhaps best assessed by Steven’s attorney in “The Trial”: “A shallow stratagem who turned on her own kind out of a misguided attachment to a planet and creatures like *these*”. Despite the many flaws in Pink Diamond/Rose Quartz, Pearl is undyingly loyal to her. Pearl is a Homeworld Gem, and a Homeworld Gem does not disobey her Diamond.
Amethyst: Homeland
In human fighting, this is usually “country”, but in Amethyst’s case, her homeland is the planet in general. Amethyst has never been to Homeworld and knows very little about it. The Earth is where she was made, grew up, came of age. To paraphrase Rupert Brooke:
A dust whom [Earth] bore, shaped, made aware,Gave, once, her flowers to love, her ways to roam,A body of [Earth]'s, breathing [Earth’s] air,Washed by the rivers, blest by suns of home.
The same way Pearl, Peridot and Lapis all long to variable extents to return to Homeworld, so too does Amethyst feel a loyalty to her home world. She is somewhat similar to a South African born to English parents, who is African even though her ancestry is not.
Steven: Family
Like any child, Steven feels compelled to follow in his parents’ footsteps; in this case, his mother’s. Like any child of a great hero, he struggles with the fact that he has some awfully big shoes to fill.
In Steven’s bit, the words “…everything that everybody wants me to be when I’m grown” are a bit ambiguous by themselves. With video supplement, i.e. the image of Rose Quartz in the background, it is abundantly clear that he knows EXACTLY what he is supposed to be. Echoing what he says in “Joy Ride”, about worrying that the Crystal Gems resent him for robbing them of Rose, he seems to be pretty locked on to the idea that he is expected to literally BE Rose Quartz. Not only that, but he feels a need to also atone for some of his mother’s sins, noting that many gems call him “Rose”, but that those are usually the same gems that are trying to kill him for Rose’s alleged war crimes.
In any case, he is fighting for his family name. On the one hand, to be as great as his mother once was, and on the other, to redeem himself of his mother’s flaws. Yes, he loves earth and the other gems, but he is really most concerned with becoming Rose Quartz.
